568 



REPORT — 1898. 



The occurrence of copper under such conditions is due to the locality, 

 and may quite possibly attain injurious proportions, for the oysters wer-e 

 obtained from a creek which is locally supposed to bring down copper, and 

 the mud of which was found by Thorpe to contain 0-148 per cent, of 

 copper. Normal sea-water contains such an excessively small quantity of 

 copper that it was not found possible to detect its presence, even electro- 

 lytically, in a litre of sea-water, after concentration. 



The green leucocytosis already referred to was first noticed by Herd- 

 man and Boyce in American oysters which had been relaid near Fleet- 

 wood. The colour manifests itself in patches and streaks of pale green on 

 the mantle, in engorgements of the l^lood vessels and in masses of green 

 coloured leucocytes in the heart. The leucocytes are apparently all 

 amoeboid wandering cells, comparable to the colourless corpuscles of the 

 blood of higher animals, and the colouration coincides with their distri- 

 bution. 



The six greenest and six whitest of 120 of these oysters were chosen 

 for analysis ; also a quantity of the greenest portions of the greenest 

 oysters was selected from another liatch, and compared with the corre- 

 sponding portions of the whitest oysters. The iron was not determined in 

 the latter comparison, owing to contamination of metal in the cutting. 



The excessive quantity of copper in the selected green oysters is 3 -75 

 times that in the white calculated per oyster, and 3-63 times calculated 

 on the ash. In the selected parts the total copper present calculated on 

 the ash is high in both cases, and the green parts again show a marked 

 excess in the proportion of 2-1 to 1. The copper and iron in the white 

 specimens are about normal, but the increased quantity of iron in the 

 green is marked, being 2-5 times that of the former. Still there is rela- 

 tively a large excess of copper as compared with iron in the green oysters, 

 as is evident from the analyses, the ratio being 1-1:1 for the white and 

 1 "8 : 1 for the green. 



It is to be concluded, therefore, that the green colour of these oysters 

 is coincident with the distribution of the excessive quantity of copper 

 present, and that the copper is in consequence to be regarded as the cause 

 of the colour. The histo-chemical investigations of Boyce and Herdman 

 have amply confirmed this conclusion. 



Further, this leucocytosis is not accompanied by a mere redistribution 

 of copper, but by an absolute increase of the amount present in the body. 



The deposition of copper in this manner is regarded by Boyce and 

 Herdman 'as a degenerative reaction, due to a disturbed metabolism, 

 whereby the normal copper of the hseiaocyanin, which is probably passing 

 through the body in minute amounts, ceases to be removed, and so becomes 

 stored up in certain cells.' The change is comparable in kind to the 

 accumulation of iron in pernicious anaemia. 



